A second or third powerline adapter needs to communicate with the one connected to the main router, so that you can access internet. Thus, your router is assigning IP address for all clients... As...

Wired connection to wpa4220 works OK?

140114 should be the latest firmware for US version. http://www.tp-link.us/support/download/?model=TL-WPA4220&version=V1#tbl_j

After upgrade the firmware, did you pair them? If not, follow this guide. http://www.tp-link.com/en/article/?faqid=258 The powerline light will be on if they are communicating with each other.

Download the utility for Windows 8.1 here. http://www.tp-link.com/en/support/download/?model=TL-PA4010&version=V1#tbl_b To pair WPA4220KIT, there are two ways. There is an instruction as well....

There is MAC utility. Now you can run the utility, login its webpage and change SSID&secure the network. ;) http://www.tp-link.com/en/support/download/?model=TL-WPA271&version=V1#tbl_j